body {
    /*设置背景图片,不平铺,水平和垂直都是居中,固定不动*/
    background: url(../images/login1.jpg) no-repeat center center fixed;
    /*保持图像本身的宽高比例，将图片缩放到正好完全覆盖定义背景的区域*/
    background-size: cover;
    padding-top: 20px;
}

button {
    width: 100px;
    height: 40px;
    background: rgb(120, 153, 245);
    position: relative;
    border-radius: 20px;
}

form {
    position: absolute;
    left: 50%;
    top: 50%;
    width: 430px;
    height: 550px;
    padding: 10px;
    margin: -300px 0 0 -215px;
    border: 2px solid #fff;
    border-radius: 25px;
    overflow: hidden;
    /*隐藏溢出内容*/
    box-shadow: 0 0 13px 3px rgba(184, 69, 238, 0.5);
    /*盒阴影：水平和垂直偏移量都为0，阴影模糊半径为13px，
	 * 阴影扩展半径为3px,黑色透明度为50%*/
}

input {
    width: 288px;
    height: 48px;
    border: 1px solid rgba(255, 255, 255, 0.4);
    border-radius: 25px;
    display: block;
    font-family: 'Sourse Sans Pro', sans-serif;
    font-size: 18px;
    color: #fff;
    padding-left: 70px;
    padding-right: 20px;
    margin: auto;
    outline: none;
    margin-bottom: 20px;
    background: rgba(174, 166, 245, 0.4) no-repeat 16px 16px;
}

.reg-bar {
    width: 360px;
    margin: 20px auto 0;
    font-size: 18px;
    overflow: hidden;
}

.reg-bar a {
    color: #fff;
    text-decoration: none;
}

.reg-bar a:hover {
    text-decoration: underline;
}

.reg-bar .reg {
    float: left;
}

.reg-bar .forget {
    float: right;
}

.border-radius {
    width: 160px;
    height: 160px;
    margin: 45px auto;
    background: url(../images/login1.png) no-repeat center center;
    border: 5px solid rgba(255, 255, 255, 0.4);
    border-radius: 200px;
}


/*设置 当光标放到type=submit上时为一只小手*/

input[type=submit] {
    cursor: pointer;
}


/*设置输入框的提示文字为白色*/

::-webkit-input-placeholder {
    color: #fff;
}


/*当该背景元素获得焦点时，设置背景颜色及盒阴影*/

input:focus {
    background-color: rgba(0, 0, 0, 0.2);
    box-shadow: 0 0 5px 1px rgba(177, 69, 240, 0.5);
    overflow: hidden;
}

.btn {
    width: 380px;
    height: 52px;
    border-radius: 4px;
    margin: 0 auto;
    background: #00B0DC;
    padding: 10.5px 21px;
    border-radius: 25px;
    color: #e1e1e1;
}


/*当鼠标悬停在该元素上时，设置边框、文字阴影、背景颜色及文字颜色*/

.btn:hover {
    border: 1px solid #253737;
    text-shadow: 0 1px 0 #333333;
    background: #00B0DC;
    color: #fff;
}


/*当该元素激活(在鼠标单击与释放之间发生的事件)时，
 *设置外边距、文字阴影、边框、背景颜色和文字颜色*/

.btn:active {
    margin-top: 1px;
    text-shadow: 0 -1px 0 #333333;
    border: 1px solid #253737;
    background: 00B0DC;
    color: #fff;
}